18 August 1868 Posted on August 17, 2012 by Staff Helium is discovered by the French astronomer Pierre Jules César Janssen Famous Words of Inspiration..."If you have built castles in the air, your work need not be lost; that is where they should be. Now put foundations under them." Henry David Thoreau — Click here for more from Henry David Thoreau Related posts: 28 July 1868 18 August 1976